Reaktion #466560

Reaktionsgleichung

N-3-pyridylpivalamide

N,N,N′,N′-tetramethylethylenediamine

iodine

n-butyllithium

→

title compound

Ausbeute 50.7%

2,2-Dimethyl-N-(4-iodo-pyridin-3-yl)-acetamide

Ausbeute 50.7%

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturAfter cooling again to −78° C.
2. 2
   workup.ADDITIONwere added dropwise during 1.5 h
3. 3
   SonstigeThe dry ice bath was removed
4. 4
   Temperaturto warm up to room temperature overnight
5. 5
   workup.STIRRINGStirring
6. 6
   workup.ADDITION1000 ml water and 1000 ml saturated sodium thiosulfate pentahydrate solution were added
7. 7
   SonstigeThe aqueous layer was separated
8. 8
   Extraktionextracted twice with 800 ml ethyl acetate
9. 9
   TrocknenThe combined organic layers were dried (magnesium sulfate)
10. 10
    Sonstigeevaporated
11. 11
    FiltrationChromatographical filtration

Vorschrift

A solution of 91 g (510 mmol) N-3-pyridylpivalamide and 230 ml (1.53 mol) N,N,N′,N′-tetramethylethylenediamine under argon in 2000 ml tetrahydrofuran was cooled in a dry ice bath to −78° C. Within 1 h, 153 ml (1.53 mmol) of a 10 N n-butyllithium solution in hexane were added dropwise. The reaction mixture was stirred at 0° C. for additional 2 h. After cooling again to −78° C., 380 g (1.5 mol) iodine dissolved in 300 ml tetrahydrofuran were added dropwise during 1.5 h. The dry ice bath was removed and the reaction mixture was allowed to warm up to room temperature overnight. Stirring was continued and 1000 ml water and 1000 ml saturated sodium thiosulfate pentahydrate solution were added. The aqueous layer was separated and extracted twice with 800 ml ethyl acetate. The combined organic layers were dried (magnesium sulfate) and evaporated. Chromatographical filtration gave 75 g (48%) of the title compound as brown crystals.

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